Erik Weaver

Discuss Rocket J-Design vs. Batch Burn Design.

o Discuss how these approaches differ in terms of burning management. For me, this is a very important item. I have discovered (after the first Winter) I did NOT like tending the sticks every few minutes.
oo Sitting beside it, or on the RMH bench, and reaching over to adjust the fire is one thing;
oo Sitting across the room, trying to write, or responding to an online forum post, or cooking dinner, is another thing.

o (And I think "well, obviously,") Include Plans for at least one iteration of the Batch Burn Design.
oo Discuss the importance of building accurately, and with precision.
ooo Specifically include designs for the port: measurements, materials, replacement, etc.
oo Discuss the greater potential heat at the bottom of the riser, and refractory material options.
oo Discuss the greater head space needed.
oo Include discussion as how to design, and calculate the proper surface area of a Bell Design.
ooo Specifically include which areas are, and are not, to be included in the surface area calculation.

o Aesthetics - "How Purdy Is It?"
oo Design options to enjoy viewing the fire.


For me, this would be an extremely interesting and important section of the book. I love the Batch designs, and they fit my personality. It would be great if this section was more than just an "adder," and was actually a full fledged attempt to provide design plans, complete with details and options. One of the books I have, does offer some nice information in this regard, but compared to the J-style, it feels as if it were just thrown in as an after thought, in that it lacks a lot of detail.

Test Builds.
I sincerely believe it is extremely important to build at least one or two of these beasts outside, to test the theory and the builder's skills. Mistakes are easy to deal with when made on top of a layer of sand outside, versus in one's living room

Supa mic wrote:I think a really good option which was suggested previously but missed in this poll was "Radiant Masonry Heater"

Which keeps the well known acronym RMH that is ubiquitous throughout the internet as seen https://www.acronymfinder.com/Science-and-Medicine/RMH.html

If we are not trying to keep the same acronym and this is only for regulatory filings, I might include "Total Combustion Radiant Masonry Heater" in place of "Rocket" shorthand.

(TC)RMH = (Total Combustion) Radiant Masonry Heater.
I like that the best so far! Great suggestion.

1. Retains the RMH. (Useful in future Internet searches, I should think.)

2. "Radiant," captures the barrel's purpose exceptionally well; and this is certainly one of the major differences to a traditional "mass heater." Therefore the change in name is practical, more descriptive, and a logical extension of the item being described.

3. And I like adding the "TC" for the "technical" description for referencing in code. This is also a logical, accurate naming convention. And since it adds two adjectives to the Technical Name, Code Nerds may like it better too, lol.

Big thumbs up!

(Quote)
Then there is stuff about codes and insurance.  All wood burning stuff is out - except masonry heater stuff.  And we say "this is a type of masonry heater" and they say "then why isn't masonry heater in the name?"
(End Quote)

Masonry Heater should certainly be in the name, for the above cited insurance and code observations.
That's why I like Masonry Mass Heater/Stove as the best re-naming. With the prefix Triple Burn as a decent descriptor.

Masonry Mass Heater/stove I like best.
2nd choice Triple Burn Mass Heater and
Montana Mass Heater third.
The first two are fairly accurate descriptions. Montana is actually misleading, but better that the really poor choices.

Hello Nick,

I cast my vote with those that say, essentially, go to the basics.
Use the proper size barrel, and double check all your math, and physical distances in your build. Double check the riser ratio and quality of insulation installation. That sort of thing.
When the geometry is right, the riser is well designed and constructed, and it can breathe, it should burn very, very hot.

I've built several rocket stoves, and they've all done well so far, but I also found that when I cut corners, or "experimented" I tended to get poor results.
My case was the chimney, which I initially did for cheaps (low cost) and therefore too short (and putting it at a decided disadvantage). Very finicky burner that was, because the draft was so iffy.
When I think about my inner spacing, and see yours, I think it looks very "cramped" and cast my vote to a choke point. The dragon must breathe!

An 8 inch rocket is truly a monster! My 6 inch is able to cook me out of my living room, breaking over 100*F in the room, and raise the temps to comfortable levels several rooms over, with a bit of electrical fan assist (1,384 sq. ft. total, and NOT designed for good airflow throughout, being built around 1950, with the idea of cheap fuel).

Good luck, and keep trying!
Erik

paul wheaton wrote:Last night I watched DVD1 as one big chunk ....   it was missing a small piece.  

Unfortunately, I made two pages of notes of things that needed to be changed/mended and then we need to look again.  So it might still be another day or two.

I for one, am glad you are going through them again, as a finished presentation, looking for errors and omissions. We've waited this long, a little while longer to help ensure completeness and quality is well worth it!

4 DVDs vs. 8 DVDs.

A point of confusion may be whether there are only 4 DVDs, as appears to be the case, and was the original idea in the kickstarter. Thus the 8-DVD set would NOT include 8 different DVDs, but rather two sets of the same 4-DVD set.

Charles Deshler wrote:Really excited to get this coming. I just finished my new shop this week and i am ready for a Rocket stove to heat with. Does anybody know what the clearance is to walls/wood floor?

It depends upon how you design the build. Are you going to use heat shielding or not? I know Ernie and Erica discuss this in their new book, "The Rocket Mass Heater" so you may wish to get a copy of that. It is also discussed in various threads, which are free but require your time to be spent in greater amounts than reading their book. You may also look to your local building codes, and the ASTM standards for masonry heaters. A RMH is a hybrid of a masonry heater and a standard wood heater: the masonry standards apply to the thermal mass (bench, bell, etc); and the wood heater standards apply to the metal barrel.

Off the top of m head, which means I may be mistaken these are nominally a 3 to 4 foot clearance from the barrel, and half that distance if properly heat shielded, and as little as 4-inches for the mass, provided the proper thickness of mass is in place (a minimum of 8-inches as I recall). So if you are able to provide 4-foot clearance all the way around, I doubt you need to worry (this includes to the ceiling, which to my mind is certainly one of the more critical concerns: heat rises, after all). Anything less, and you need to take a careful look at your design parameters.

Not so much a specific answer, as it is a procedural answer ...which I think is best, not knowing what design you plan to build.

And always take extra precautions with the exit flue/chimney. Observe best building practices here, all the way around, paying extra attention to through-wall/ceiling and height of the chimney (insulated or multiple walled pipe is recommended in most cases, and may be required by your code - you won't know until you look at your local building codes). My opinion is that it is best to purchase pre-fab pieces for the through wall/ceiling and outdoor chimney - basically all the flue/chimney elements once they exit your RMH. And pay attention to the clearances.

Assuming you build the RMH as it is described in the literature found on this forum, on Donkey's forum, and in the few recommended books (again, Ernie and Erica's new book is probably the single best resource on that point now), the most dangerous elements are going to be how you exit the exhaust. I recommend being conservative in this area, whether you have local building codes or not, I would strongly recommend observing best building practices for your exhaust.

On a personal note, given how inexpensive temperature probes and thermometers are, I would plan to build several of these into your RMH at critical heat areas, so that you may observe these critical temperatures during operation.